The invention relates to a device and a method for portioning a flow of individual products, such that the products on the input side are supplied in one conveying plane and the products on the output side are distributed on at least two conveying planes arranged above one another for discharging the products.
The device and the method according to the invention may be used, for example, in combination with a packaging machine, the conveyed products being packaged thereby. The individual products may be, for example, fragile products of the confectionery or long-life bakery industry, such as for example cookies, chocolate products and the like. However, in addition to products of the food industry, for example, technical products are also conceivable such as electronic or electrical components, machine elements, pharmaceutical or medical products, and the like, which typically are produced and distributed in large quantities and which are supplied in sequence to a corresponding packaging carrier or packaging material. However, the method and the device according to the invention may also be used, for example, in the field of storage and transport logistics in connection with piece goods, packages and the like.
For example, a method and a device for filling a multiple-row packaging tray with individual products are disclosed in WO 2012/038475 A2, in particular a so-called tray-loading packaging machine. In this known packaging machine, batches of individual itemized products are formed, said products being transferred in sequence to a packaging tray at the end of a conveying path. The present invention may be used, for example, within the context of such a packaging machine.
In such packaging machines, the individual products are typically conveyed in rows and lanes located adjacent to one another and/or behind one another in a continuous flow by means of suitable conveying devices. The conveying devices are typically circulating endless conveyor belts, the products being located thereon and supplied to a downstream processing step, for example the transfer in sequence to a packaging container. In this case, the situation may occur that this downstream processing step causes technical problems by, for example, the malfunction of devices or machine parts or portions of the machine provided therefor. In such cases, however, it is undesirable to stop the entire machine system since the individual products typically on the input side are constantly supplied in large quantities, for example from a continuous product manufacturing process. Thus it is to be avoided that the entire system has to be stopped if only a specific partial region of the system malfunctions due to technical problems or errors. In known packaging machines, therefore, generally a second substantially identical machine part or portion of the system is provided for possible replacement of that machine part or area of the system which may potentially have technical problems. As soon as the first machine part, therefore, operates in a faulty manner or completely malfunctions, the products may be immediately diverted to the replacement machine part or replacement portion of the system. In this manner, the constant product flow supplied on the input side may pass unhindered and without interruption through the entire system.
Whilst normally, i.e. without the malfunction of the potentially problematical area of the machine, the products are continuously conveyed on the belt conveyor devices substantially in one plane or on one level, if the relevant first area of the machine malfunctions, said products are diverted to a different conveying plane or a different conveying level, on which they are conveyed to the aforementioned replacement area of the machine. To this end, the packaging machine may have a diverter in the conveying path, for example an adjustable or pivotable region of a conveying device or a pivotable partial conveyor belt, the products being able to be supplied thereby to one or the other downstream conveying plane, depending on the pivoted position.
Due to the aforementioned continuous uninterrupted supply of products on the input side of the entire machine, in particular in the case where the products are conveyed bearing closely against one another, i.e. substantially without spacing from one another, the further problem arises here that even during the phase of adjusting or pivoting the conveying device the products are supplied from one conveying plane to the other conveying plane whilst continuing to move on the conveyor belt. Therefore, it has to be ensured that the products are always able to be transferred to one of the two conveying planes continuously and in sequence, without it resulting in, for example, a blockage in the product flow. In particular, in the phase of adjusting or pivoting a relevant conveyor belt portion from one conveying level to a different conveying level, the supplied products are also not allowed to fall into an empty space at a front open edge of the conveyor belt in the direction of conveyance.
To this end, in the known conveying systems or packaging machines, batches of products are formed in the direction of conveyance, i.e. a batch of products is separated from the supplied continuous product flow in the direction of conveyance, by the products forming the batch being conveyed further at a higher conveying speed, following a specific interface in the conveying device, for example with a downstream second conveyor belt. In this manner, a spacing or a gap is formed between the product batch produced and the downstream continuous product flow.
Whilst the separated product batch, therefore, may be transferred to the first conveying plane which follows downstream, the gap formed behind this product batch is used so that the aforementioned conveyor belt portion subsequently has sufficient time in order to be pivoted, such that from now on a connection to the aforementioned second conveying plane is produced (whereby the connection to the first conveying plane is interrupted) so that the following products then may be supplied to the second conveying plane. The products may be supplied, therefore, via this second conveying plane to a functionally operational machine unit downstream, whilst the conveying path formed by the first conveying plane may be brought to a standstill in a phased manner or fully, so that for example the errors or problems of a machine unit arranged downstream of this first conveying path may be corrected.
It goes without saying that a pivoting of the conveyor belt from a first conveying plane to a second conveying plane, and optionally subsequently also to further conveying planes, may not only be used as a safety feature for bringing individual conveying path sections to a standstill, for example when machine units have malfunctioned, but also for other applications, such as for example the intentional, successive supply of product batches to different conveying planes in order to supply the product batches, for example in a targeted manner, cyclically to downstream processing steps in each case.
In the known conveying systems or packaging machines, the aforementioned formation of a leading product batch, which is separated from a continuous product flow by forming a gap, may be implemented, for example, by means of two circulating conveyor belts arranged directly behind one another. In this case, the first conveyor belt in the direction of conveyance of the products has a front or leading end and/or a front or leading edge in the direction of conveyance which is able to be advanced over a predetermined path in the direction of conveyance and which is subsequently able to be pulled back again counter to the direction of conveyance, whilst the conveyor belt moves the products further in the direction of conveyance. A second circulating conveyor belt is directly adjacent to this first circulating conveyor belt, said second conveyor belt having a rear or trailing end and/or a rear or trailing edge in the direction of conveyance which is able to be advanced over a predetermined path counter to the direction of conveyance and which is able to be pulled back in the direction of conveyance, whilst this second conveyor belt conveys the products. Each of the aforementioned two conveyor belts is a so-called “pull-nose conveyor belt” so that the interconnection of these two conveyor belts may be denoted as a “double pull-nose conveyor belt”.
The system of movement of these two pull-nose conveyor belts arranged one behind the another is also visible, for example, in FIG. 1 of the accompanying drawings which shows the device according to the invention and in which the products are conveyed from left to right. In principle, in FIG. 1 the conveyor belt shown on the left-hand side may be compared with the aforementioned first conveyor belt which has its leading edge in FIG. 1 on its right-hand side (i.e. in the center of this drawing). In principle, in FIG. 1 the aforementioned second conveyor belt may be compared with the upper conveyor belt shown on the right-hand side, which has its trailing edge on its left-hand side, i.e. once again in the center of FIG. 1.
The aforementioned desired product batch is separated from the continuous product flow by the actual product conveying speed of the first conveyor belt being less than the product conveying speed of the second conveyor belt, the separated product batch being conveyed further thereon. At the same time, the rear edge of the second downstream conveyor belt opposing the direction of conveyance of the product moves below the products of the continuous product flow, back to a position of the product flow at which the product batch is intended to be separated from the product flow. Due to the greater conveying speed of the second conveyor belt, the product batch formed moves away from the trailing product flow in the direction of conveyance, whereby the gap is formed between the leading product batch and the trailing product flow and becomes successively larger. As soon as the gap which has been formed has reached the desired size which correlates with the time period of the above-described pivoting of the downstream conveyor belt portion between the two conveying planes, the above-described cycle starts from the front, i.e. the rear edge of the second conveyor belt passes again counter to the direction of conveyance below the products supplied in the continuous flow as far as the position at which the next product batch is intended to be separated from the product flow.
To the extent that the rear trailing edge of the second conveyor belt in this case is advanced counter to the direction of conveyance, the front leading edge of the first conveyor belt is pulled back counter to the direction of conveyance. In this case the two edges of the two conveyor belts are located substantially directly behind one another or bear against one another, so that in the transition from the first to the second conveyor belt in any case the product conveyance is not impaired, i.e. the products, for example, are not damaged or do not fall off the conveyor belts.
In a corresponding manner but in reverse, in the phase of gap formation, i.e. the removal of the separated product batch, the leading edge of the first conveyor belt is advanced in the direction of conveyance and at the same time the trailing edge of the second conveyor belt is pulled back in the direction of conveyance. In this case, the speed of the advance of the front edge of the first conveyor belt substantially corresponds to the product conveying speed of the first conveyor belt, whereby the products of the continuous product flow, as it were relative to the front edge of the first conveyor belt, are brought to a standstill, i.e. in this phase the products in the product flow do not substantially move relative to the front edge of the first conveyor belt although they are still conveyed further in the direction of conveyance by this conveyor belt.
As has been set forth above, the spacing formed between the separated product batch and the trailing continuous product flow serves to span the time which is required for pivoting a downstream partial conveyor belt from a first conveying plane, to which a first product batch is supplied, to a second conveying plane, to which a downstream product batch is supplied. As has also been described above, a second conveying plane, for example, may be required as a safety measure if a machine unit in the conveying path of the first plane malfunctions due to technical problems, so that this conveying path has to be shut down and the products have to be diverted to the second conveying path. If, however, such a product diversion is not required and the first conveying path is available unchanged, the product batches are still conveyed with a spacing from one another due to the above-described gap formation. Apart from this safety measure, however, the spacing formed generally has no further function and may even interfere with the further continuous processing (for example packaging) of the products. In particular, it may be necessary for the spacing formed between the individual successive product batches in the further sequence of the processing process to have to be removed again, i.e. a continuous product flow is formed again from the successive individual product batches. This requires additional technical measures which would be unnecessary if initially the spacing between the leading product batch and the trailing continuous product flow had not been formed.